Guitar plug



FIG. 1 is perspective view showing my design;

FIG. 2 is a front view showing my design;

FIG. 3 is a back view showing my design;

FIG. 4 is a left side view showing my design;

FIG. 5 is a right side view showing my design;

FIG. 6 is a top plan view showing my design; and,

FIG. 7 is a bottom plan view showing my design.

The broken lines are included for the purpose of illustrating portions of the guitar plug and form no part of the claimed design. 

CLAIM The ornamental design for a guitar plug, as shown and described. 